The global positioning system (GPS) capabilities of cargo ships, oil tankers and other vessels stuck in the Middle East because of the widening war are likely worse than those in your cell phone.

Experts say this deficiency explains why since the start of U.S.-Israeli strikes, the jamming of satellite navigation signals has left about 1,000 ships in the Persian Gulf and the Gulf of Oman unable to determine their location, either momentarily or continuously.

Dimitris Ampatzidis, a senior risk and compliance analyst for the energy market intelligence firm Kpler, said the number represents about half of the vessels in the area.